A method of an open loop characterization of an electrostatic MEMS based resonator with a varying gap, the method including: converting, via a trans-impedance amplifier circuit, an output current signal of the resonator into a voltage; multiplying the output current signal converted into the voltage, by means of a multiplier circuit, with an AC signal or with a different signal at a frequency of the resonator and carrying a second harmonic signal to a main tone; and measuring a frequency response of a signal cleared of frequencies apart from the main tone using a network analyzer.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.

A microelectromechanical resonant switch (resoswitch) converts received radio frequency (RF) energy into a clock output. The resoswitch first accepts incoming amplitude- or frequency-shift keyed clock-modulated RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the carrier clock waveform. The resulting output derives from the clock signal that originally modulated the RF carrier, resulting in a local clock that shares its originator's accuracy. A bare push-pull 1-kHz RF-powered mechanical clock generator driving an on-chip inverter gate capacitance of 5 fF can potentially operate with only 5 pW of battery power, 200,000 times lower than a typical real-time clock. Using an off-chip inverter with 17.5 pF of effective capacitance, a 1-kHz push-pull resonator would consume 17.5 nW.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

An electrical circuit assembly can include a semiconductor integrated circuit, such as fabricated including CMOS devices. A first lateral-mode resonator can be fabricated upon a surface of the semiconductor integrated circuit, such as including a deposited acoustic energy storage layer including a semiconductor material, a deposited piezoelectric layer acoustically coupled to the deposited acoustic energy storage layer, and a first conductive region electrically coupled to the deposited piezoelectric layer and electrically coupled to the semiconductor integrated circuit. The semiconductor integrated circuit can include one or more transistor structures, such as fabricated prior to fabrication of the lateral-mode resonator. Fabrication of the lateral-mode resonator can include low-temperature processing specified to avoid disrupting operational characteristics of the transistor structures.

Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

An integrated circuit may include a resonator formed from FinFET devices. The resonator may include drive cells of alternating polarities and sense cells interposed between the drive cells. Each of the drive cells may include at least two drive transistors having fins coupled to a drive terminal. Each sense cell may include two sense transistors having one fin coupled to a sense terminal and another fin coupled to ground. Adjacent drive and sense cells may be separated by an intervening region that can accommodate a number of fins. Configured in this way, the resonator can exhibit a high quality factor, low phase noise, and can operate at a frequency that is less than the characteristic resonant frequency as defined by the fin pitch of the drive and sense transistors.

An electrical circuit assembly can include a semiconductor integrated circuit, such as fabricated including CMOS devices. A first lateral-mode resonator can be fabricated upon a surface of the semiconductor integrated circuit, such as including a deposited acoustic energy storage layer including a semiconductor material, a deposited piezoelectric layer acoustically coupled to the deposited acoustic energy storage layer, and a first conductive region electrically coupled to the deposited piezoelectric layer and electrically coupled to the semiconductor integrated circuit. The semiconductor integrated circuit can include one or more transistor structures, such as fabricated prior to fabrication of the lateral-mode resonator. Fabrication of the lateral-mode resonator can include low-temperature processing specified to avoid disrupting operational characteristics of the transistor structures.